The function of the Protein Production Shared Resource (PPSR) is to stimulate and support interdisciplinary research among Cancer Center members and translate discoveries in the molecular and cellular biology of cancer to the disciplines of biochemistry, structural biology and chemical biology. The importance of protein science in Cancer Center research will grow in the post-genomic era. Pure proteins are essential for progress and the Protein Production Shared Resource is a focus of expertise and equipment for providing Cancer Center investigators at St. Jude Cancer Center access to these vital reagents. The PPSR employs state-of-the- art technology to produce proteins and protein domains in large quantities for detailed biochemical and structural analysis. Efficient protein purification is facilitated by contemporary high-resolution chromatography systems, and the facility is equipped with automated crystallization screening equipment. The PPSR services are divided into four modules: (a) subcloning open reading frames into expression vectors; (b) expression of tagged proteins in a bacterial system; purification of the protein product; and (d) preliminary crystallization trials. We accept genes cloned into an appropriate vector for expression in bacterial systems. The protein is then purified by affinity, size exclusion and/or anion exchange chromatography. Crystallization trials are initiated using a CyberLab Robotic workstation. Crude extracts may also be submitted for purification of the protein of interest, or a pure protein submitted for crystallization trials. The resource is designed to be a high throughput facility, focused on performing achievable goals.